Controlling the operation of gas furnaces equipped withsecondary electrical power source(s)

Abstract

A method for controlling the operation of a gas furnace equipped with one or more secondary electrical power sources is disclosed. The method comprises the steps of switching the gas furnace to a secondary power mode in an event of loss of a primary electrical power source associated with the gas furnace, wherein the gas furnace alternately switches between an ON state for a first prolonged time, and an OFF state for a second prolonged time, at a frequency of an optimized number of cycles per hour.

1 . A method for controlling operation of a gas furnace equipped with one or more secondary electrical power sources, the method comprising the steps of:
 switching the gas furnace to a secondary power mode in an event of loss of a primary electrical power source associated with the gas furnace, wherein the gas furnace alternately switches between an ON state for a first prolonged time, and an OFF state for a second prolonged time, at a frequency of an optimized number of cycles per hour.   
     
     
         2 . The method of  claim 1 , wherein the one or more secondary electrical power sources comprise a battery and a thermoelectric generator, wherein the method comprises the steps of:
 enabling the thermoelectric generator to generate electrical power from heat generated by the gas furnace during the ON state; and   charging the battery and/or operating the gas furnace using the electrical power generated by the thermoelectric generator.   
     
     
         3 . The method of  claim 1 , wherein the one or more secondary electrical power sources comprise a battery and a solar power generation system, wherein the method comprises the steps of operating the gas furnace using the solar power generation system during daytime to build and utilize residual heat in an area of interest (AOI) to be heated by the gas furnace. 
     
     
         4 . The method of  claim 1 , wherein the one or more secondary electrical power sources comprise a battery, a solar power generation system, and a thermoelectric generator, wherein the method comprises the steps of:
 operating the gas furnace using the solar power generation system during the daytime which enables the thermoelectric generator to generate electrical power from the heat generated by the gas furnace; and   operating the gas furnace using the electrical power generated by the thermoelectric generator during the secondary power mode and/or during nighttime.   
     
     
         5 . The method of  claim 1 , wherein the gas furnace alternately switches between the ON state and the OFF state based on one or more of characteristics of a thermostat associated with the gas furnace, a thermal load factor, and a thermostat preset temperature to be maintained at an AOI by the gas furnace. 
     
     
         6 . The method of  claim 1 , wherein during the secondary power mode, the method comprises the step of keeping the gas furnace in the ON state for the first prolonged time such that the gas furnace remains in the ON state for a longer time period after the preset temperature is achieved at the AOI, to heat the AOI to a first temperature above the preset temperature of the AOI, allowing for bigger temperature swings. 
     
     
         7 . The method of  claim 6 , wherein the method further comprises the step of keeping the gas furnace in the OFF state for the second prolonged time once the first temperature is achieved at the AOI, such that the temperature at the AOI drops to a second temperature below the preset temperature of the AOI, allowing for bigger temperature swings. 
     
     
         8 . The method of  claim 1 , wherein the length of the cycle which includes the ON state and the OFF state of the gas furnace is longer during the secondary power mode than during the primary-power mode. 
     
     
         9 . The method of  claim 1 , wherein during the secondary power mode, the method further comprises steps of adjusting one or more control settings of the gas furnace to conserve electrical power stored in the one or more secondary electrical power sources,
 wherein the method of adjusting the one or more control settings comprises one or more of adjusting operating speed of a blower associated with the gas furnace to a lowest speed setting with optimized ramp changes during switching ON and OFF of the blower, increasing an ON-delay time of the blower to a first predetermined first value followed by a controlled ramp up of the blower, reducing the OFF-delay time of the blower to a second predetermined value ending with a controlled ramp down of the blower, and adjusting an input level of the gas furnace to a lowest level.   
     
     
         10 . The method of  claim 1 , wherein during the secondary power mode, the method further comprises the steps of:
 switching OFF a thermostat associated with the gas furnace;   sensing temperature of return air to the gas furnace and correspondingly determining a temperature of an area of interest (AOI) to be heated by the gas furnace, wherein the return air is received from the AOI, and   controlling the operation of the gas furnace and/or the one or more secondary power sources to maintain a preset temperature at the AOI.   
     
     
         11 . The method of  claim 1 , wherein during the secondary power mode, the method further comprises the steps of:
 switching OFF a thermostat associated with the gas furnace;   operatively connecting the gas furnace to one or more temperature sensing devices present at the AOI to detect a temperature of the AOI, wherein the one or more temperature sensing devices comprise a low-power wireless sensor, a smart home device, a smart smoke detector, and a smart air purifier; and   controlling the operation of the gas furnace and/or the one or more secondary power sources to maintain a preset temperature at the AOI.   
     
     
         12 . A control device for controlling operation of a gas furnace equipped with one or more secondary electrical power sources, the control device comprises:
 a processor coupled to a memory storing instructions executable by the processor,   wherein the control device is operatively connected to the gas furnace, a primary electrical power source, and one or more secondary electrical power sources, and   wherein the control device is configured to switch the gas furnace to a secondary power mode in an event of loss of the primary electrical power source, wherein the gas furnace alternately switches between an ON state for a first prolonged time, and an OFF state for a second prolonged time, at a frequency of an optimized number of cycles per hour.   
     
     
         13 . The control device of  claim 12 , wherein the control device is a thermostat installed at an area of interest (AOI) to be heated by the gas furnace. 
     
     
         14 . The control device of  claim 12 , wherein the control device is in communication with a thermostat associated with the gas furnace. 
     
     
         15 . The control device of  claim 12 , wherein the one or more secondary electrical power sources comprise a battery, and a thermoelectric generator, wherein the control device is configured to:
 enable the thermoelectric generator to generate electrical power from heat generated by the gas furnace during the ON state; and   charge the battery and/or operate the gas furnace using the electrical power generated by the thermoelectric generator.   
     
     
         16 . The control device of  claim 12 , wherein the one or more secondary electrical power sources comprise a battery, and a solar power generation system, wherein the control device is configured to operate the gas furnace using the solar power generation system during daytime to build and utilize residual heat in an area of interest (AOI) to be heated by the gas furnace. 
     
     
         17 . The control device of  claim 12 , wherein the one or more secondary electrical power sources comprise one or more of a battery, a solar power s generation system, and a thermoelectric generator, wherein the control device is configured to:
 operate the gas furnace using the solar power generation system during the daytime which enables the thermoelectric generator to generate electrical power from the heat generated by the gas furnace; and   operate the gas furnace using the electrical power generated by the thermoelectric generator during the secondary power mode and/or during nighttime.   
     
     
         18 . The control device of  claim 12 , wherein the control device increases the length of the cycle which includes the ON state and the OFF state based on one or more of characteristics of a thermostat associated with the gas furnace, a thermal load factor, and a thermostat preset temperature to be maintained at an AOI by the gas furnace. 
     
     
         19 . The control device of  claim 12 , wherein during the secondary power mode, the control device is configured to keep the gas furnace in the ON state for the first prolonged time such that the gas furnace remains in the ON state for a longer time period after the preset temperature is achieved at the AOI, to heat the AOI to a first temperature above the preset temperature of the AOI, allowing for bigger temperature swings. 
     
     
         20 . The control device of  claim 19 , wherein the control device is configured to keep the gas furnace in the OFF state for the second prolonged time once the first temperature is achieved at the AOI, such that the temperature at the AOI drops to a second temperature below the preset temperature of the AOI, allowing for bigger temperature swings.